Electric furnace tail gas treatment system

Abstract

The utility model discloses an electric furnace tail gas treatment system which comprises an electric furnace, the upper portion of the electric furnace is provided with a flue gas main pipe used for conveying flue gas during high-load or low-load work of the electric furnace, and the flue gas main pipe is sequentially connected with a first fan, a settling chamber, a cooling chamber and a bag-type dust collector which are used for purifying the flue gas during high-load work of the electric furnace. A flue gas bypass pipe used for purifying flue gas during low-load work of the electric furnace is in bypass connection with the flue gas main pipe, a purifying and heating assembly is connected to the flue gas bypass pipe and comprises a heating pipe connected with the flue gas bypass pipe, filters are arranged on the inner sides of a flue gas inlet and a flue gas outlet of the heating pipe, and a second fan is connected to an outlet of the heating pipe; according to the low-load flue gas treatment device, the bypass pipe and the purifying and heating assembly are additionally arranged for flue gas treatment during low-load operation of the electric furnace, the problems of equipment clogging, 'bag pasting 'and the like caused by too low temperature can be effectively avoided, and the purifying efficiency and safety are improved.

Description

Technical Field

[0001] This utility model relates to the field of electric furnace production technology, and specifically to an electric furnace exhaust gas treatment system. Background Technology

[0002] During electric arc furnace smelting, the flue gas temperature fluctuates with changes in production load. The flue gas generated by the electric arc furnace has a high temperature (usually 200℃~400℃). Traditional processes require the flue gas to be cooled to a suitable temperature (about 100℃~150℃) first through a waste heat boiler or water spray cooling system, and then filtered by purification equipment such as bag filters, and finally formed clean coal gas to be transported to power plants for power generation.

[0003] However, when the electric furnace is running at low load, the flue gas will still be purified through the high-temperature flue gas pipeline. However, due to the reduced smelting intensity, the flue gas temperature drops significantly (possibly below 100°C). If the original purification process is still used, the flue gas temperature will drop further to below the dew point, which will cause the gas purification equipment to be prone to blockage. At the same time, the filter bags will frequently experience "clogging" due to the humidity and impurities of the flue gas, which will seriously affect the normal operation of the equipment.

[0004] In addition, harmful components in low-temperature flue gas are prone to condensation inside the equipment, which not only reduces purification efficiency but may also cause poisoning accidents due to residual gas during personnel maintenance, posing a significant safety hazard. Utility Model Content

[0005] To address the aforementioned problems, this utility model provides an electric furnace exhaust gas treatment system.

[0006] This utility model is achieved through the following technical solution:

[0007] An electric furnace exhaust gas treatment system includes an electric furnace. A main flue gas pipe is installed at the top of the furnace for conveying flue gas during high-load or low-load operation. The main flue gas pipe is sequentially connected to a first fan for purifying the flue gas during high-load operation, a settling chamber, a cooling chamber, and a bag filter. A bypass pipe for purifying the flue gas during low-load operation is connected to the main flue gas pipe. A purification and heating assembly is connected to the bypass pipe. The purification and heating assembly includes a heating pipe connected to the bypass pipe. Filters are installed on the inner sides of the flue gas inlet and outlet of the heating pipe. A second fan is connected to the outlet of the heating pipe. The outlet of the second fan is connected to the bag filter through the bypass pipe and delivers the exhaust gas to the user.

[0008] Alternatively, control valves may be installed on both the main flue gas pipe and the flue gas bypass pipe.

[0009] Alternatively, a first temperature probe may be installed at the front end of the flue gas main pipe.

[0010] Alternatively, the heating tube may have a heating wire spirally wound inside and tightly attached to the inner wall, and a heat insulation layer on the outside of the heating tube. The heating wire is electrically connected to a voltage signal generator, which is electrically connected to an external power supply.

[0011] Optionally, an automatic temperature control system is also installed on the flue gas bypass pipe. The automatic temperature control system includes a PLC controller, which is electrically connected to a second temperature probe installed at the inlet and outlet of the heating tube, electrically connected to a first temperature probe, electrically connected to control valves installed on the main flue gas pipe and the flue gas bypass pipe, and electrically connected to a voltage signal generator.

[0012] Compared with existing technologies, the beneficial effects of this utility model are as follows: This utility model addresses the flue gas treatment during low-load operation of electric furnaces by adding a bypass pipe and a purification and heating component, and also includes an automatic temperature control system. This system can adjust the flue gas pipeline according to different operating conditions, effectively avoiding problems such as equipment blockage and "bag clogging" caused by excessively low temperatures, improving purification efficiency, reducing maintenance rate, ensuring operator safety, optimizing gas quality, and meeting power generation needs. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the system of this utility model;

[0014] In the diagram: 1. Electric furnace; 2. Flue gas main pipe; 3. First fan; 4. Settling chamber; 5. Cooling chamber; 6. Bag filter; 7. Flue gas bypass pipe; 8. Heating pipe; 9. Filter; 10. Second fan; 11. Control valve; 12. First temperature probe; 13. Heating wire; 14. Voltage signal generator; 15. PLC controller; 16. Second temperature probe. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments:

[0016] like Figure 1 As shown, an electric furnace exhaust gas treatment system includes an electric furnace 1. The upper part of the electric furnace 1 is equipped with a main flue gas pipe 2 for conveying flue gas during high-load or low-load operation. The main flue gas pipe 2 is sequentially connected to a first fan 3 for purifying the flue gas during high-load operation, a settling chamber 4, a cooling chamber 5, and a bag filter 6. A bypass pipe 7 for purifying the flue gas during low-load operation is connected to the main flue gas pipe 2. A purification and heating assembly is connected to the bypass pipe 7, including a heating pipe 8 connected to the bypass pipe 7. Filters 9 are installed on the inner sides of the flue gas inlet and outlet of the heating pipe 8. A second fan 10 is connected to the outlet of the heating pipe 8. The outlet of the second fan 10 is connected to the bag filter 6 through the bypass pipe 7 and delivers the exhaust gas to the user.

[0017] The control valve 11 is arranged on the flue gas main pipe 2 and the flue gas bypass pipe 7.

[0018] The first temperature probe 12 is arranged at the front end of the flue gas main pipe 2.

[0019] The heating pipe 8 is internally provided with the heating wire 13 which is spirally wound and closely attached to the inner wall, and the heating pipe 8 is externally provided with the heat insulation layer. The heating wire 13 is electrically connected with the voltage signal generator 14, and the voltage signal generator 14 is electrically connected with the external power supply.

[0020] The automatic temperature control system is further arranged on the flue gas bypass pipe 7, and the automatic temperature control system comprises the PLC controller 15. The PLC controller 15 is electrically connected with the second temperature probe 16 arranged at the inlet and outlet of the heating pipe 8, electrically connected with the first temperature probe 12, electrically connected with the control valve 11 arranged on the flue gas main pipe 2 and the flue gas bypass pipe 7 respectively, and electrically connected with the voltage signal generator 14.

[0021] The implementation principle of the electric furnace tail gas treatment system in the embodiment of the application is as follows:

[0022] When the electric furnace 1 is working, the first temperature probe 12 can judge whether the electric furnace 1 is in the low load stage by collecting the flue gas temperature in the flue gas main pipe 2. When the first temperature probe 12 detects a temperature higher than the set temperature (the set temperature is determined according to the site condition, and the set value is usually lower than 100 DEG C), the first temperature probe 12 sends a signal to the PLC controller 15. The PLC controller 15 sends an instruction to open the control valve 11 on the flue gas main pipe 2 and close the control valve 11 on the flue gas bypass pipe 7, and starts the first fan 3 to deliver the high-temperature flue gas to the settling chamber 4 for settling. After settling, the flue gas enters the cooling chamber 5 for cooling. Finally, the flue gas is filtered by the bag filter 6 to form clean gas which is delivered to the power plant for power generation.

[0023] When the first temperature probe 12 detects a temperature lower than the set temperature, the first temperature probe 12 sends a signal to the PLC controller 15. The PLC controller 15 sends an instruction to close the control valve 11 on the flue gas main pipe 2 and open the control valve 11 on the flue gas bypass pipe 7, and starts the second fan 10. Meanwhile, the PLC controller 15 sends a signal to the voltage signal generator 14 to supply power to the heating wire 13. After the heating wire 13 is powered, the heating pipe 8 inside the heating pipe 8 is heated. When the low-temperature flue gas enters the heating pipe 8, the low-temperature flue gas is mixed with the high-temperature air in the heating pipe 8, and the temperature can be directly increased by more than 100 DEG C (the temperature is suitable for the bag filter and will not be higher than 150 DEG C). When the low-temperature flue gas enters or is discharged from the heating pipe 8, the low-temperature flue gas is filtered by the filter 9 and then discharged to the bag filter 6 for filtering to form clean gas which is delivered to the power plant for power generation.

[0024] When the low-temperature flue gas is heated, the low-temperature flue gas after heating is detected by the second temperature probe 16, and after the detection is completed, the signal is sent to the PLC controller 15; when the detected temperature is lower than 100 DEG C, the PLC controller 15 sends a signal to the voltage signal generator 14 to increase the input voltage of the heating wire 13; at this time, the temperature in the heating tube 8 will rise, so that the temperature of the low-temperature flue gas passing through will rise; when the detected temperature is lower than 150 DEG C, the PLC controller 15 sends a signal to the voltage signal generator 14 to lower the input voltage of the heating wire 13; at this time, the temperature in the heating tube 8 will decrease, so that the temperature of the low-temperature flue gas passing through the heating will decrease, ensuring that the appropriate temperature enters the bag-type dust collector 6, preventing the occurrence of the bag sticking phenomenon of the low-temperature flue gas and the deformation phenomenon of the high-temperature flue gas, thereby reducing the maintenance rate and ensuring the safety of the operating personnel.

[0025] The basic principle, main features and advantages of the utility model are shown and described above. The skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments, and the above-mentioned embodiments and the description in the specification are only to illustrate the principle of the utility model, and the utility model will have various changes and improvements without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model claimed. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. An electric furnace exhaust gas treatment system, comprising an electric furnace (1), wherein the upper part of the electric furnace (1) is provided with a flue gas main pipe (2) for conveying the flue gas during its high-load or low-load operation, and the flue gas main pipe (2) is sequentially connected to a first fan (3), a settling chamber (4), a cooling chamber (5), and a bag filter (6) for purifying the flue gas of the electric furnace (1) during high-load operation, characterized in that: The main flue gas pipe (2) is connected to a bypass pipe (7) for purifying the flue gas when the electric furnace (1) is operating at low load. The bypass pipe (7) is connected to a purification and heating component. The purification and heating component includes a heating pipe (8) connected to the bypass pipe (7). The inner side of the flue gas inlet and outlet of the heating pipe (8) is provided with a filter (9). The outlet of the heating pipe (8) is connected to a second fan (10). The outlet of the second fan (10) is connected to the bag filter (6) through the bypass pipe (7) and transported to the user.

2. The electric furnace exhaust gas treatment system according to claim 1, characterized in that: Both the main flue gas pipe (2) and the bypass flue gas pipe (7) are equipped with control valves (11).

3. The electric furnace exhaust gas treatment system according to claim 2, characterized in that: The front end of the flue gas main pipe (2) is equipped with a first temperature probe (12).

4. The electric furnace exhaust gas treatment system according to claim 1, characterized in that: The heating tube (8) is provided with a heating wire (13) that is tightly attached to the inner wall and spirally wound inside. The heating tube (8) is provided with a heat insulation layer on the outside. The heating wire (13) is electrically connected to a voltage signal generator (14), and the voltage signal generator (14) is electrically connected to an external power supply.

5. The electric furnace exhaust gas treatment system according to claim 1, characterized in that: An automatic temperature control system is also provided on the flue gas bypass pipe (7). The automatic temperature control system includes a PLC controller (15). The PLC controller (15) is electrically connected to the second temperature probe (16) at the inlet and outlet of the heating tube (8). The PLC controller (15) is electrically connected to the first temperature probe (12). The PLC controller (15) is electrically connected to the control valve (11) installed on the main flue gas pipe (2) and the flue gas bypass pipe (7) respectively. The PLC controller (15) is electrically connected to the voltage signal generator (14).

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